1. Field
One or more exemplary embodiments relate to motion estimation of a video image, and more particularly, to hierarchical motion estimation performed on a reduced image.
2. Description of the Related Art
In general, image compressing methods, such as Moving Picture Experts Group (MPEG)-1, MPEG-2, MPEG-4 Visual, H.261, H.263, and H.264/MPEG-4 advanced video coding (AVC), compress image data by splitting a frame into a plurality of macro blocks, performing prediction on the macro blocks, obtaining prediction blocks, and converting and quantizing differences between an original image block and the prediction blocks.
There are two types of prediction methods; inter prediction and intra prediction. The intra prediction performs prediction on a current block by using data of peripheral blocks present in a current frame. The inter prediction performs block based motion prediction and generates a prediction block corresponding to a current block from previously encoded one or more video frames.